RandomTask

I’ve managed to kill 3 of them w/in the last month. One was bad before I even fired the motor. Replaced it. That one went bad at the race track 11 hours in. . .. The one I replaced it with was DOA. So had to do another.



This is aggravating beyond belief. These are all second gen units that seemingly can’t last worth a damn. What makes these things fail? It shouldn’t be rocket surgery to make an optical encoder.



Is there a ROCK SOLID replacement for these units? From my research, going to the MSD unit doesn’t really help you. Trying not to spend a bunch of money but at the same time, sick and tired of switching them out. . .



Thanks!

Tom400CFI

NO.

They're ALL a crap shoot. Buy the cheapest one you can get with the best warranty. (Sac City, right now, I think).

Hey...at least your cooling system is getting good maintenance! Assuming you're not dumping the old coolant back in.

vette196

contact the optidoctor....you could PM him on here or I could give you his email address

bigtoys

The only time I've had to replace mine (so far!), I bought an Accel unit for around 130.00 I think. Two years ago, still going strong. Not a DD, but a regular weekend driver.

FWIW, I agree with Tom400CFI: Buy cheap and keep your fingers crossed.

yd328

Which ones did you have the problems with?

Gary

Pete919

PatternDayTrader

Once mine takes the final dump, this is my plan.

pacoW

The AIP unit from Sac City vette has a 2 yr warranty and they are pleasant to deal with. The most important thing right now for opti replacement (to me) is the warranty. Bad enough they're a bitch to change out, free replacement is a must IMO.

RandomTask

When I originally built the motor, I put in a brand new unit from a local parts store "thinking" it would avoid any trouble down the road. Wrong. It was completely dead.

Put the original unit back in. Ran fine until it died at the track.
Replaced it with another brand new unit from a parts store. Dead.
Replaced it with a used unit from a LT1 - works (so far).



Just running water wetter and distilled water. Aggravating wasting brand new water wetter. Not as aggravating as when the oil level sensor randomly backed out of the canton oil pan spraying about $100 of oil all over a fast section of the track. . .

2LZ

I bought the AIP from Sac City. Then got ****, took it apart, put my "known good" Mitsu sensor in it (after a good cleaning), locktighted the rotor screws and sealed it back up with RTV.
The downside? Shot my two year warranty out the door by tearing it apart and replacing parts.
The upside? Known good sensor and a guaranteed sealed unit with a rotor I know won't fly off. It's a toss up.
Car's been running great.

TorchTarga94

Good Luck.

PLRX

I never get these threads. How can you kill 3 units within a year??

My 92 had 85K miles when I bought it, the dealer replaced the opti and it lasted for 120K miles.

92-94 were non-vented

sstonebreaker

Make sure your vacuum line to the opti is working correctly. I don't know if it's condensation or ozone buildup or what, but if your vacuum line is pinched or clogged, the opti will crap out quick. Make sure that little disk-shaped check valve in the vacuum line is working and installed facing the proper way.

Smokeysvette

I agree I bought two opti's from Sac-City for my two 92's and one failed within the last two weeks of the TWO YEAR warranty and since then both have been trouble free. IMHO Best was the guys (and Norma) at Sac-City. they were great to work with even though I was right at the end of the two warranty and would have been out of warranty waiting for them to check it and send it back. Chris said no problem, we'll take care of you.....and they did just that. Ive seen others go out and buy expensive opti's with the same result and fail or arrive DOA. So like others say why do it because it's crap shoot. At least Sac-City has excellent customer service and they aren't expensive. So that's a big plus

Renfield

You can buy the exact same AIP unit from Amazon for less than $100 with a 90 day warranty. Sac city has a special arrangement with AIP offering the 2 year warranty for some $60+ more. I bought the Amazon because like you I took it apart and did the locktite thing, so the warranty is on me. I left their sensor installed.

My $350 Petris Optispark died within 2 years from a bad bearing. Optidoc is relatively new to the game and expensive like Chris Petris. But I've already spent too much on a supposed well regarded unit to try yet another. They're all a crapshoot.

On the positive side, after having done three I'm getting better and faster at replacement.

twichy2011

By being the unluckiest person, or having another underlying problem that causes the opti to fail. I was in the same shoes he was in, and it turned out that the front of the intake was leaking oil onto the opti and causing it to fail. Oil will kill these units in a heartbeat!

2LZ

Indeed. I read about Sac City here...and of course, pass through Sac on my commute so I stopped by and got one. I wanted it as a scarecrow as the original was still cruising along at 128k. I was just going to bolt it on when needed but then got the brainy idea over a beer to tear it apart to do a recon. That's when I decided to tear the old one off and toss in my Mitsubishi sensor, locktite the rotor screws and seal it all. Then of course, found the AIP unit direct from Amazon for less. Oh well, I really didn't expect to tear it down. I just can't help myself sometimes.
The stocker is all cleaned up and ready to go....but I can't locate the real, double shouldered bearing. I pressed in the single shoulder but it wiggles regardless of which direction I install it. I'm not sure what the Optidoctor uses. These things aren't rocket science. It's just a matter of having a good sensor and keeping it sealed.

Tom400CFI

Oil doesn't kill them, it simply contaminates the lenses. You can CLEAN THE LENSES and get 'em working again.

Greg Gore

I think the AC Delco units are the best but then I don't like anything from the aftermarket. I've never had trouble with one but I did change one at 100K for preventive maintenance.

JayhawkCPA

What about doing the coil pack conversion?